Quick-acting thermal relay



Dec. 27, 1927.

R. J. WENSLEY QUICK ACTING THERMAL RELAY Filed April 6, 1923 2 Sheets-Sheet 1 mm W m V./ O R WITNESSES:

ATTORNEY Dec. 27, 1927.

R. J. WENSLEY QUICK ACTING THERMAL RELAY Filed ADril 6, 1923 2 Sheets-Sheet 2 INVENTOR Roy J Wens/ey ATTORNEY Patented Dec. 27, 1927.

UNITED 'STATEiPATENT OFFICE.

ROY J. WENSLEY, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELEQTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

QUICK-ACTING THERMAL RELAY.

My invention relates to relays and particularly to quick acting relays.

One object of my invention is to provide a relay embodying a switch device and means for quickl actuating the switch device to one of a p urality of positions in accordance with external conditions.

Another object. of my invention is to provide a relay, of the above-imlicated character, embodying an element responsive to an external thermal condition, such, for example, as the temperature of a bearing of an apparatus, and a switching mechanism that shall be so controlled by the thermally-responsive element as to etlect a. quick operation thereof.

A further object of my invention is to provide a relay, of the above-indicated character, that shall be. rugged in structure and positive. and reliable in operation, and that shall be self-resetting or non-resetting, as may be desired.

In practicing my invention for the protection of machine bearings, I utilize an expansible bellows member, commonly known as a sylphon tube,-whieh is connected to a bulb containing a volatile fluid that is adapted to expand when the bulb containing the same is subjected to a temperature equal to, or exceeding, a predetermined value. A quick-acting switch mechanism including a contact member is controlled by the bellows member to etfect quick engagement and disengagement of the contact member with one of a plurality of stationary contact members. The switch mechanism comprises a toggle mechanism for controlling the contact member, a spring tending to break the toggle quickly when the links are moved out of alinement, and a pivoted member controlled by the thernial-responsivc element for controlling the. movement of one of the. links of the toggle.

Figure l of the, accompanying drawings is a front elevational view of the relay cmbodying my invention with the contact member of the switch in one position.

Fig. 2 is a front elevational view of the relay, illustrating the switch in another position.

Fig. 3 is a front elevational view of a modified form of the switch shown in Figs. 1 and 2, and

Fig. 4 is a front elevational view of a portion of the control member of the relay.

Application filed April 6, 1923. Serial No. 630,277.

The relay that is illustrated in the accompanying figures comprises an actuatim bellows member 1 that is influenced by tl ie internal pressure exerted thereupon by a volatile-fluid in a bulb 2 which is subjected to the temperature of a bearing 3 to protect the hearing from overhcatimz. The bulb 2 and the bellows member 1 coinprise a closed system within which the volatile tluid and the resulting vapor are confined.

The bellows member 1 has mounted thereon an insulating member 4, such as micarta or hard rubber, which is actuated bv the bidlows member 1 through a guiding bracket 5 to control the movement of a switching mechanism (3 in accordance with the pressure developed within the bellows member. as determined by the temperature of the bulb 2.

The switching mechanism 6 comprises a movable contact member 7 that is supported on, and controlled by. a link 8 that co-opcrates wrth a link 9 to constitute a toggle mechanism whereby the contact member 7 may be actuated to engage the one or the other of two stationary contact members 10 and 11.

The toggle mechanism comprising the links 8 and S) is adapted to be quickly broken by a spring 12 when the links are moved out of ahnement by a pivoted member 13, the operation of which is controlled through an adjustable member H by the insulating member l which is mounted on the bellows member 1.-

The member 13 is pivoted on a shaft 15 that is supported in part by a casting 16. The pivoted member 13 is maintained in positive engagcnnrnt with the insulating member 4 by means' ola relatively strong spring 17 that is sccnrcd to (he mid of tlic pivoted member. The othcr end of thc pivoted member is provided with a slot l8 and a head portion 1!) constituting a latch. The slot 18 is arranged to accommodate a pin 20 that is disposed in a portion of the link 9 that is extended beyond the hinge pin :21 that operatively connects the links 8 and 9.

The pin 21 is secured to the casting 1G and both ends of the toggle are therefore free to turn about the pin 21 as a center. A spring 22, which is connected between a pin 23 that is anchored in the casting 16 and the pin 20 that is disposed in the extended portion of the link 9, serves to assist in quickly actuating the toggle from one position to another by means of the force impressed u on the link member 9 after it is so moved y the pivoted arm 13 as to place the operating torque of the spring 22 on one side or the other of the stationary pin 21 relative to a line drawn between the pins 20, 21- and 23.

he position of the switch mechanism that isillustrated in Fig. 2 is the sition' assumed by the several elements a ter the bellows member has been operated sufficiently to effect the movement of the contact member 7 from the stationary contact member 10 to the stationary contact member 11.

To actuate the mechanism to the position that is illustrated, the pivoted member 13 engages the in in the link 9 and forces it past the pm 21. Simultaneously, the link 9 is straightened out to aline with link 8, and as soon as the pin 20 is moved past the pin 21 out of direct alinement with the pins 21 and 23, the spring 22 becomes efl'ective to assist in straightening or alining the links 8 and 9 to form the,toggle and then breaking the toggle onthe other side. As soon as the toggle is broken on the left-hand side, the

spring 12 passes beyond the line drawn between the free ends of the links 8 and 9 and also serves to assist in breaking the toggle quickly, thereby moving the contact member 7 with a snap action from the contact member 10 to the contact member 11.

With a pivoted member of the construction that is illustrated in Figs. 1 and 2 embod ing thehead portion 19, the switching mec anfsm will be reset in its initial posi' tion upon the cooling of the volatile fluid and the consequent reduction in pressure in the bellows member.

If the self-resetting of the switching mechanism is not desired, the head portion 19 may be removed to provide a pivoted element, as is illustrated in Fig. 3. Means may be provided for removably securing the portion 19 to the main part of the pivoted memarrangements of the various elements that are illustrated but may be modified in the terms and scope of the invention, as defined in the appended claims.

I claim as .my invention:

1. A switch device comprising a contact member, a toggle mechanism comprising two links for actuating said contact member from an initial position, aspring disposed be-' tween one end of each of the links, means for turning one link about-a hinge'of the toggle mechanism as a pivot, a pivoted member for. controlling said means, and an overcenter spring connected to said means for normally maintaining said toggle mechanism in its initial position.

2. A switch device comprising a. movable contact member, a pivoted member for controlling the contact member, a spring for controlling the movement of the pivoted member, a second pivoted member for controlling the effectiveness of the spring, an over-center spring for the second pivoted member, a third pivoted member for controlling the second pivoted member, a spring for restraining the third pivoted member,

and thermally-actuated means for impress-- ing an operating force on the third pivoted member.

In testimony whereof, I have hereunto subscribed my name this 29th day of March, 1923.

RO Y J. WENSLEY. 

